Add test coverage for non-visible turbo-cable-streams-ource tags

Author: excid3

test/dummy/app/views/messages/show.html.erb

@@ -1,6 +1,6 @@
 <h1>Message #<%= @message.id %></h1>
 
-<%= turbo_stream_from @message %>
+<%= turbo_stream_from @message, style: "display: none" %>
 
 <div id="<%= dom_id @message %>">
   <%= render @message %>

test/system/broadcasts_test.rb

@@ -123,7 +123,7 @@ class BroadcastsTest < ApplicationSystemTestCase
   private
 
   def reconnect_cable_stream_source(from:, to:)
-    cable_stream_source = find("turbo-cable-stream-source[signed-stream-name=#{signed_stream_name(from)}]")
+    cable_stream_source = find("turbo-cable-stream-source[signed-stream-name=#{signed_stream_name(from)}]", visible: :all)
 
     cable_stream_source.execute_script <<~JS, signed_stream_name(to)
       this.setAttribute("signed-stream-name", arguments[0])